Science Scoops: Crime Scene Insects

by Stephen James O'Meara

“CSI: Crime Scene Insects,” a new exhibit making a world tour (booked through 2007), explores the rapidly growing field of forensic entomology— in other words, how maggots and insects found at a crime scene can provide investigators with clues and help bring murderers to justice (see the January 2004 “Crime Scene Science” issue of ODYSSEY).

“It's really kind of exciting,” says Lee Goff, the exhibits curator and chairman of the forensic sciences program at Chaminade University in Honolulu, HI. “It's a chance to bring something to people that 20 years ago I don't think anyone would have been interested in.”

Here's the buzz. The types of insects on a body and their stages of development can help determine the time elapsed since the death occurred. They can also provide clues to the cause of death, where the victim was killed, and whether drugs or other toxins might have been involved. For example, in Hawaii, blowflies will start laying eggs on a corpse within 10 minutes of death. The eggs, in turn, hatch into maggots, which morph into pupae, which emerge from their shells as adult flies. Other insects show up later, Goff says—some to nibble on the corpse, some to prey on the other bugs, some to do both.

Insects' development is so predictable and their behaviors so reliable that courts allow them as evidence. “They're predictable and they really don't care,” Goff says. “And as long as you do a nice objective analysis of what's going on, and you kind of follow their trail of evidence, they're going to bring you to the truth about what happened.”

The interactive exhibit gives visitors of all ages and interest levels the chance to sort through insect evidence at simulated crime scenes, and then try to solve the cases. “It's a little graphic, but they see worse stuff on prime-time TV,” Goff says.

Vocabulary

Activity

Are blowflies herbivores, omnivores, or carnivores? Why?[anno: Blowflies are carnivores because they feed on animal flesh.]

What kind of animals do you think eat blowflies? Draw a food chain that includes a dead body, blowflies, and other members of that food chain.[anno: Food chain diagrams will vary but should include a corpse, blowflies, and blowfly predators, such as birds. Students might include plants and animals that a corpse fed upon when the organism was still alive.]